WWA Info Exchange

Question for members here. I would appreciate any help. I import small quantities of wood products from China. The woodcraft on these items are good. The problem is, that though the finish also looks good, it scratches and scrapes off very easily. I have asked the factory what they type of finishing they use, but havnt been able to understand their reply. I believe they said it was PE or PU, but not sure. Anyone have any idea what the possible causes for this might be ( though I figure there might be many).

Also, if anyone knows a wood finishing consultant (specially in the NJ area) would appreciate if you could send me a message.

Thanks

BUMP

No telling what the Chinese finish is. Could be anything, but probably whatever is cheapest to buy and apply. Very soft, likely a poor quality polyurethane or varnish from the sound of it.

You could take a piece to a lab and get it tested and know for sure what it is.

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I bring to life, I bring to death:
The spirit does but mean the breath:
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Hey Design,

Traditional Chinese and Japanese lacquer is called urushi and is made from the sap of a rather toxic tree of the same family as poison oak. The application of urushiol is a slow and meticulous process, so if these items are finished cheaply, it's probably not urushi, but there's always the possibility that a thin layer was applied.

Tom

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Mohandas K. Ghandi

Daub somewhere you can afford a smudge with ethyl alcohol. If the finish softens - shellac.

Daub with lacquer thinner. If the finish did not soften with alcohol, but does now - some sort of lacquer. Betting it is not the sumac type. http://en.wikipedia.org/wiki/Urushi

If it's impervious to both, you've got a "varnish" of some sort. Soft finishes suggest long oil base and alkyd resin, but if it is urethane, as the U suggests, there's really not a big difference. Long oil formulation and satin additives make a soft finish.

Doesn't sound like one which is VOC law compliant. They're hard as a rock.

Thanks for replies. Actually, I was now told by factory that it is Polyurethane.
Question is what are the possible reasons for this ease of scratching and scraping. Is it necessarily the quality of PU or other factor.

There are ASTM and ISO standards for poly. I'd suggest you ask your supplier to provide evidence of compliance to one or more of the applicable standards. Note that Chinese companies are not obligated to abide by US or International standards for anything, although some do if they are exporting.

There have been many problems with this aspect of Chinese exports on a variety of products as I'm sure you are aware - occasionally one will make the news. There was a huge problem with their plywood a few years back, and I'm not sure if it has been resolved yet.

This organization may be able to assist you, and they have info regarding the various product standards that apply in the US. http://www.polyurethane.org/s_api/sec.a ... 4&DID=4059

Good luck.

PS: Getting to the bottom of this may be very time consuming and frustrating, and may not be worth the effort. I dealt with these kinds of issues in the aerospace industry for quite a few years. It is not an easy task, and often leads to somebody getting lawyered up.

_________________
I bring to life, I bring to death:
The spirit does but mean the breath:
I know no more. (Tennyson, In Memoriam)

Is there no other source other than China for these items?

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Nullum Gratuitum Prandium

Cheers - Dennis

My shop!

Re: The finish... maybe, if you are interested in 'toughening' up the finish, you can coat it with a coat of dewaxed shellac and add a few coats of your favorite varnish. The shellac is an excellent sealer...

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[quote="Tampa Tom
Re: The finish... maybe, if you are interested in 'toughening' up the finish, you can coat it with a coat of dewaxed shellac and add a few coats of your favorite varnish. The shellac is an excellent sealer...[/quote]

Sounds like throwing a board over sand. The board may be rigid, but the sand is still soft.

Sounds like throwing a board over sand. The board may be rigid, but the sand is still soft.[/quote]

But, you can sand surf!

_________________
* http://tomsworkbench.com
* Purveyor of the world's finest Weasel Spit
* Why do they call it a WORKshop if I go there to have fun?
* Founding member: WWAFLAUX#1
* Passed 16,000 posts 7/23/09 - 8:41 a.m.